Effect of Therapeutic and Supratherapeutic Doses of Vonoprazan on the QT/QTc Interval in a Phase I Randomized Study in Healthy Subjects

This phase I, randomized, 4‐period, 4‐sequence, double‐blind, active‐ and placebo‐controlled, crossover study assessed the effects of vonoprazan on the QT/QTc interval in healthy subjects. Subjects received single oral doses of vonoprazan 40 mg, vonoprazan 120 mg, moxifloxacin 400 mg (positive control/open label), and placebo. The primary end point was time‐matched, placebo‐corrected, baseline‐adjusted mean Fridericia‐corrected QT interval (ddQTcF). Of 64 subjects (mean age, 37.8 years; 50% male), 63 received all four regimens. One subject discontinued due to nondrug‐related adverse event of tonsillitis. Assay sensitivity was established; lower bound of the one‐sided 95% confidence interval (CI) for ddQTcF was >5 ms between 1.5 and 12 h following moxifloxacin administration. For both doses of vonoprazan, the one‐sided upper 95% CI ddQTcF did not exceed 10 ms. There was no correlation between plasma vonoprazan concentrations and increases in ddQTcF. Vonoprazan was well tolerated. No severe adverse events/deaths were reported. (European Clinical Trials Database Registry: 2011‐004003‐20.)